Linda Esserman of UC-San Francisco and Ian Thompson of UT-San Antonio analyzed the results of breast and prostate cancer screenings going back 20 years, and found they didn't keep people alive:

Screening may be increasing the burden of low-risk cancers without significantly reducing the burden of more aggressively growing cancers and therefore not resulting in the anticipated reduction in cancer mortality.

The study concludes "new approaches for screening, early detection, and prevention" should be considered.

And there's good reason. Esserman and Thompson have identified an epidemic of overtreatment. Folks are being torn up inside-and-out by cancers that won't kill them and they're not getting help on cancers that will.

Esserman has the right perspective on this. She told The New York Times we're just going to have to find better screening procedures. Science isn't perfect. "There is no free lunch."